Modified configure script to work on Athena.

[kyle-augustson]

There is a flag (--for-athena) that triggers one of two options for either GNU or CRAY compilers [can add intel/aocc if wanted]. This along with the --with-blas and --with-lapack flags allows the use of Cray's libsci on Athena so things build cleanly, you just need to specify the library path with $CRAY_LIBSCI_PREFIX; same for fftw --with-fftw=$FFTW_ROOT.

Here's the currently loaded modules for the Cray environment:

module list
Currently Loaded Modulefiles:

1. cray-libpals/1.8.0 5) xpmem/1.0.1-1.5_1_gfb6998056825 9) libfabric/12.0 13) PrgEnv-cray/8.7.0
2. cray-pals/1.8.0 6) cray-fftw/3.3.10.11 10) craype-network-ofi
3. craype-x86-turin 7) cce/21.0.0 11) cray-mpich/9.1.0
4. perftools-base/26.03.0 8) craype/2.7.36 12) cray-libsci/26.03.0

To use GNU module unload PrgEnv-cray and module load PrgEnv-gnu. At runtime, be sure to add the libmpi path to your LD_LIBRARY_PATH for some reason that doesn't seem to be provided by the module properly. For the cray config that is

/opt/cray/pe/mpich/9.1.0/ofi/CRAY/20.0/lib

for GNU it is

/opt/cray/pe/mpich/9.1.0/ofi/GNU/11.2/lib

[tukss]

This looks good. I was wondering if we should try to handle the Cray environments more generally. We also have them on all the DOE systems. So far I've always used the spack package to integrate those and it worked pretty well.

I'm fine with merging this now and improving on it during the hackathon.

[tukss]

Do you remember why this was necessary? I've added it back then because we had similar defines for Intel and GNU. I think the only place we it matters is where we have nonstandard routines like SIGNAL.
CRAY_COMPILER is not used anywhere in the source at the moment, so it shouldn't make a difference.

[kyle-augustson]

That's why I got rid of it, but left the original in the file in case it popped up at some point.